Closed fluid-operated free-pump system with three parallel tubings



March 18, 1952 c, J, COBERLY CLOSED FLUID-OPERATED FREE-PUMP SYSTEM WITHTHREE PARALLEL TUBINGS 2 SHEETS-SHEET 1 Filed May 16, 1949 LI IML' March18, 1952 c. J. COBERLY CLOSED FLUID-OPERATED FREE-PUMP SYSTEM WITH THREEPARALLEL TUBING-S 2 SHEETS-SHEET 2 Filed May 16, 1949 [VVE/VTOPJ(2425/1/05 d 6055? Patented Mar. 18, 1952 UNITED STATES assasn CLOSEDFLUID-OPi'sIItATED FREE-PUMP SYS- TEM WITH THREE PARALLEL TUBINGSClarence J. Coberly,:Los Angeles, Calif., assignor, by mesneassignments, to Dresser Equipment grliliiipany, Cleveland, Ohio, acorporation of Application May 16, 1949, Serial No. 93,483

, 32 Claims. 1

' My invention relates in general to tubing systems 'for fluid-operatedwell pumps and, more particularly, .to a closed tubing system for afluid- 5; operated well pump of the so-called free" type.

Reference is hereby made to my copending applications Serial No. 93,482,filed May 16,1949, Serial No. 93,484, filed May 16, 1949, and Serial No.93,481, filed May 16, 1949.

It is conventional in the oil industry to employ a well pumpingapparatus which includes a free fluid-operated pump, such a pump beingmovable into and out of the well through a tubing set in the well andbeing adapted to assume an operat-: ing position at the lower end ofsuch a tubing. 51

Examples of such fluid-operated, free-pump systems are disclosed in myPatents Nos. 2,230,830,

grantedFebruary 4, 1941, and 2,338,903, granted foregoing character, thespent operating fluid discharged by the motor section of the pump isJanuary 11, 1944'.

. In conventional fluid-operated, free-pump systems,. such as thosedisclosed in my aforemen-l tio'ned patents, two tubings are employed,one for I are intermixed and conveyed upwardly together through theproduction tubing. Since the operconveying operating fluid downwardly inthe wellf to the pump and the other for conveying fluid produced by thewell upwardly therein from the pump to'the surface, the two tubingsbeing re-' ferred to hereinafter as the supply and producf tion tubings,respectively. In such conventional systems, the pump is movable into itsoperating ous provision of such fresh operating fluid reposition throughthe supply tubing. The supply and production tubings are interconnectedat. their lower ends in fluid communication with'cgy each other and withthe well so that the pump-,-;. may receive operating fluid from thesupply tubing and well fluid fromthe well and so that it may dischargewell fluid into the production tubing as production fluid.

In installing such a free pump in the well,fi t is moved downwardlythrough the supply tubing into its operating position at the lower endther'eof either by the action of gravity or by the appli cation of fluidpressure to the upper endof the pump. After the pump has been installedin its operating position, operating fluid, which is M usually cleancrude oil, is delivered to the motor section of the pump underrelatively high pressure through the supply tubing. As is well known inthe art, such operating fluid is alternately- 5 directed by'a' suitablevalve mechanism in the motor section of the pump to opposite ends of a3,

motor piston which is coupled to a pump piston in the pump' section ofthe device, fluid from the o well being admitted to th pump section by'asuitable-valve mechanism therein. Such alterthe ends of the motor pistonproduces reciprocation of the motor and pump pistons with the resultthat the pump piston pumps fluid produced by the well into theproduction tubing, the latter conveying the production fluid upwardlytherein to the surface. When removal of the pump from the well isdesired for any reason, as for service or repair, fluid pressure isapplied to the lower end of the pump to move it upwardly out of itsoperating position and through the supply tubing to the surface This isaccom plished conventionally by reversing the flow through the system sothat operating fluid flows downwardly in the production tubing tothelower end of the pump and acts on the pump to move it upwardly throughthe supply tubing to the surface.

In a conventional free-pump system of the delivered to the productiontubing so that the spent operating fluid and the production fluid atingfluiddelivered to the pump through the supply tubing must be clean, inorder to prevent abrasion and corrosion of the moving parts of the pump,fresh operating fluid must be supplied to the system continuously. Thiscontinuquires considerable surface equipment, normally inthe form ofsettling tanks or filters, which .is expensive to install and operate.Also, in the particular arrangement hereinbefore mentioned wherein thepump is disposed. in the supply tubing, the flow reversal necessary toremove the pump from the well may carry any sand or other foreign matterpresent in the production fluid into the supply tubing with the resultthat such foreign matter may enter the motor section of the pump uponresumption of operation after" reinstallation with the attendantpossibility of damage to the pump.

In view of the foregoing, it is a primary object of this invention toprovide a closed system for thefluid-operated, free pump which includesa third tubing separate from the supply and pro:

duction tubings for returning the spent operating fluid tothe surfaceindependently'of the well fluid, the tubing for returning the spentoperating fluid being referred to hereinafter as the: return tubing.With such ,a closed system, the

" spent operating fluid is separately conveyed back to the surface forstorage and re-use-to actuate.

hating application of operating fluid pressure to pi 5 thefluid-operated pump so that'there is very little loss of operating fluidfrom thesystern and,

consequently, the surface equipment necessary to supply fresh operatingfluid to the system needs have only a relatively small capacity and canbe relatively cheap and economical, both as regards initial cost andoperating costs. Also, he reversed flow necessary to move the pumpupwardly to the surface during removal of the pump may take placethrough the return tubing to avoid carrying sand and other foreignmatter into that portion of the system reserved for the operating fluid,which is an important feature. As will be pointed out in more detailhereinafter, further objects of the invention reside in certainmodifications of the pump and in the tubing arrangements employed toprovide such a closed system.

Considering the invention more specifically,

an object thereof is to provide a closed system for a fluid-operated,free pump comprising supply, return and production tubings which are setin the well and. one of which is adapted to receive the pump and toprovide an operating position for the pump at its lower end, the supply,return and production tubings respectively being adapted to conveyoperating fluid for actuating the pump downwardly into the well to thepump, spent operating fluid discharged by the pump upwardly in the wellfrom the pump to the surface, and production fluid discharged by thepump upwardly in the well from the pump to the surface.

Another object is to provide such a closed system wherein the threetubings are in erconnected at their lower ends in fluid communicationwith each other and with the well so that the pump may, when in itsoperating position, re-

ceive operating fluid for its actuation from the supply tubing throughan intake, discharge spent operating fluid into the return tubingthrough an exhaust, receive well fluid from the well through an inlet,and discharge well fluid into the production tubing through an outlet.

Another object is to provide a closed system having means whereby adownward flow of fluid through one of the tubings, other than the tubingin which the pump is disposed, may be applied to the lower end of thepump to move it upwardly out of its operating position and through thetubing in which it is disposed to the surface whenever removal of thepump from the well is desired.

Another object is to provide a closed system which includes a tubularpump receiver disposed at the lower end of and in alignment with thetubing through which the pump is movable, the pump receiver being, ineffect, an extension of suchtubing and providing the aforementionedoperating position for the pump. A related object is to provide a pumpreceiver having a seat at its lower end for the the pump being seated onsuch seat when it is in its operating position.

Another object is to provide a pump receiver 7 having passages whichplace the interior thereduction tubing, respectively, when the pump isdisposed in the pump receiverand seated on the pump seat.

Another object is to provide sealing means for normally preventingdirect flow between the tubings and the well by way of the pump receiver when the pump is in its operating position so that operatingfluid may flow only from the supply tubing through the motor section ofthe pump to the return tubing and so that well fluid may flow only fromthe well through the pump section of the pump to the production tubing.More specifically, an object in this connection is to provide a sealingmeans which, when the pump is in its operating position, places thesupply tubing in fluid communication with only the intake of the pump,the return tubing in fluid communication with only the exhaust of thepump, the well in fluid communication with only the inlet of the pumpand the production tubing in fluid communication with only the outlet ofthe pump.

Another object is to provide a system where in the aforementionedsealing means comprises annular sealing elements which are carried bythe pump adjacent various of the ports, such as the intake, etc.,therein and which are engageable with the inner wall of the pumpreceiver to prevent direct flow between the tubings.

Another object is to provide passage means communicating at one end withone of the tubings, other than the tubing aligned with the pumpreceiver, and at its other end with a chamber in the pump receiverbetween the pump seat and the pump for applying a downward flow of fluidthrough such tubing to the lower end of the pump to move it upwardly outof the pump receiver and to the surface.

Another object is to provide a sealing device for normally preventingfluid flow between two of the tubings by way of the aforementionedpassage means and the pump receiver when the pump is in its operatingposition. Other objects in this connection are to provide a systemwherein the aforementioned sealing device is a spring-loaded valve inthe passage means and a system wherein the sealing device is an annularsealing element adapted to be disposed between the pump and the pumpreceiver.

Another object is to provide a system wherein the tubing with which theaforementioned passage means communicates is the return tubing so thatthe pmnp may be moved upwardly to the surface by a downward flow ofclean fluid through the return tubing to prevent introducing sand andother abrasive matter into the pump receiver.

Still another object is to provide a closed system wherein the pump ismovable into its operating position in the pump receiver through the 1supply tubing and wherein the pump is movable out the production tubing,which is an important feature.

Another object is to minimize the power required to overcome frictionbetween the production fluid moving upwardly through the productiontubing and the wall of the production tubing by employing a productiontubing having a large internal diameter. This feature is particularlyimportant under well conditions such that a motor and/or pump sectionsof maximum capacity, which is an important feature.

Another object is to facilitate paraihn control in such a closed systemby limiting contact of the production fluid to the production tubing, i.el, by disposing the supply and return tubings without the productiontubing.

An important object of the invention is to provide a closed systemwherein the supply, return and production tubings are set in the wellside-by-side so that the downward flow of operating fluid and the upwardflows of spent operating fluid and production fluid contact only theirrespective tubings.

The foregoing objects and advantages of the present invention, togetherwith other objects and advantages thereof which will become apparent,may be attained through the employment of the exemplary embodiments ofthe invention which are illustrated in the accompanying drawings andwhich are described in detail hereinafter. Referring to the drawings:

' Fig. 1 is a utility view of a closed, fluid-operatied. free-pumpsystem which embodies the in vention; n

Figs. 2 and 3 are enlarged, horizontal sectional views respectivelytaken along the broken lines 2-2 and 3 -3 of Fig. 1;

Figs. 4 and 5 are enlarged, vertical sectional views respectively takenalong the irregular broken lines 4-4 and 55 of Figs. 2 and'? Fig.

Bbeing a downward continuation of Fig. 4;

Fig. 6 is a utility view ofanother embodiment of the invention; Figs. '7and 8 are enlarged, horizontal sectional views respectively taken alongthe broken lines 1-! and 8-8 of Fig. 6; l

Figs. 9 and 10 are enlarged, vertical sectional views respectively takenalong the. broken lines 99 and I -H] of Figs. 7 and 8; and,

Fig. 11 is an enlarged, vertical sectional view taken along the brokenline' II--II of Fig. 7.

Referring particularly to Fig. l of' the drawiings, the numeral Idesignates a well casing which is set in an oil well with its lower endopen to an oil producing formation adjacent the well as is well known inthe art, the casing being provided with a casing head I6 at its upperend. Set in the well within the casing I5 and con: nected to the casinghead I6 is a closed tubing system which comprises supply, return andproduction tubings set side-by-side andrespectively designated by thenumerals I I, I8 and I9. As will be discussed in more detailhereinafter, the supply, return and production tubings I'I, I8 and I9are interconnected at their lower ends in fluid communication with eachother and with the well by a tubular pump receiver 26 which is alignedwith and which, in effect, forms a downward extension of one of thetubings, the pump receiver being aligned with the supply tubing I! intheparticular embodiment presently under consideration. The pumpreceiver12il provides an operating position for a fluid-operated, freepump 2I- which is movable downwardly through the supply tubing I! intoits operating position in the pump receiver, the internal diameter of inmore detail hereinafter. the pump head 29 are supply, return andproducthe pump receiver being substantially equal to that of the supplytubing. As will be discussed in more detail hereinafter, the supplytubing I! is adapted to convey operating fluid, such as .clean crudeoil, under pressure downwardly in the well from the surface to the pump2| to actuate the pump, and the return tubingI8- is adapted to receivespent operating fluid discharged by the pump and to convey the spentoperating fluid upwardly in the well to the surface. The pump 2| isadapted to receive well fluid from the well and to discharge it into theproduction tubing I9 as production fluid, the production tubingconveying the production fluid upwardly inthe well to the surface.

In the particular construction illustrated, the lower ends of thetubings II, I8 and I9, and the pump receiver 20, are enclosed by a gasanchor 22 having a perforated barrel 23 which is closed fatits upper andlower ends by heads 24 and 25, respectively, the upper head havingsuitable openings therethrough for the tubings. The gas anfchor 22 issecured to the pump receiver by a "bolt 26 connecting the lower head tothe-pump receiver. V ;;The supply, return and production tubings I], I8and I9 are connected at their upper 'ends' to a pump head 29 havingvalve means (not shown) therein which is operable from the surface by ahandle 30 to direct flows of fluid through the tubings in the propermanner as will be, discussed Also connected ;to

tion lines 3I, 32 and 33 which, during operation of the pump 2I, areadapted to be connected in fluid communication with the supply, returnand production tubings Ii, I8 and I9, respectively, by

the valve means in the pump head. The supply line 3I leads to asuitablesource (not shown) of operating fluid under pressure, whichsource may be a conventional triplex pump having its intake connected toa suitable reservoir." The return line 32 leads to the reservoir, andthe production "line 33 leads to a suitable point of disposal or storagefor the production fluid. As disclosed in my aforementioned Patent No.2,338,903, the pump head 29 may also include a suitable pump catcher(not shown) for the pump 2I, the latter having at its upper end atapered head 35 which is receivable by the pump catcher during removalof the pump from the well.

Referring now to Figs. land 5 of the drawings,

the pump receiver 2i! is, as previously indicated,

aligned with and connected to the lower end of the supply tubing If, thepump receiver having at its upper end a sleeve which is threaded ontothe lower end of the supply tubing. The lower end of the sleeve 49 isthreaded into the upper end of a major bore 4! in an upper fitting 42which forms part of the pump receiver .20, a

I sleeve 43 being threaded into the lower end of the major bore 4|. Thelower end of the sleeve 43 is threaded into the upper end of a majorbore 44 in a lower fitting 45 of the pump receiver 20, an inlet sleeve46 which communicates at its lower end with the well through theperforated gas anchor barrel 23, being threaded into the lower end ofthe major bore 44.

The upper fitting 42. of the pump receiver 20 ispi ovided with aminorbore ifl into which the lower end of the return tubing I8 isthreaded,

the minor bore 49 communicating withthe major bore 4,!) in the fitting..42 through a lateral pas: sagev 5c in this fitting and through aregistering pcrtfii in a liner 52 which is'disposed in the major bore4|. The lower fitting 45 of the pump receiver 20 is provided with aminor bore 54 into which the lower end of the production tubing I9 isthreaded, the minor bore 54 communicatin with the major bore 44 in thefitting 45 through a lateral passage 55. Thus, with this construc tion,the pump receiver 20 interconnects the lower ends of the supply, returnand production tubings ll, 18 and iii in fluid communication with eachother and with the well.

The upper fitting 42 of the pump receiver 2%! is provided with a passagemeans 58 for applying a downward flow of fluid through the return tubingIt to the lower end of the pump 21 to move the pump upwardly out of thepump receiver 2i) and through the supply tubing H to the surface whenremoval of the pump is desired for any reason, this passage meanscomprising a longitudinal passage 59 which communicates at its upper endwith the minor bore 39 in the fitting 62 and which communicates at itslower end with a chamber 60 in this fitting. The passage means 58 alsoincludes a lateral passage 5| which connects the chamber (iii to themajor bore 4! in the fitting 42 through an annular groove 62 in thisfitting. Disposed in the chamber 60 is a spring-loaded valve 63, whichprevents flow of fluid from the return tubing I8 into the interior ofthe pump receiver 26 during normal operation of the pump 2|, and whichis adapted to open to permit such flow in response to'a downward flow offiuid through the return tubing l8 during removal of the pump from thewell, as will be discussed in more detail hereinafter.

The minor bore 54 in the lower fitting 45 of the pump receiver 28contains a standing valve 56 which. is adapted to prevent downward flowof fiuid' from the production tubing l9 into the interior of the pumpreceiver but which is adapted to open to permit upward flow ofproduction fluid discharged by the pump 2| into the production tubing.The valve 65 is provided with spring fingers 51 which engage shoulders68 in the minor bore 54 to hold the valve in its operating position, andincludes an inside spear fitting 69- which is adapted to be engaged by asuitable tool lowered into the well through the production tubing [9when removal of the valve is desired, as is well known in the art. 7

Disposed in the lower end of the major bore 44 in the lower fitting 45of the pump receiver and extending downwardly into the inlet sleeve 45is an inlet fitting 12 for the pump 2|, the latter having an inlet whichis adapted to receive well fluid from the well through the inlet fittingwhen the pump is in its operating position, as will be discussed in moredetail hereinafter. As is well known in the art, the inlet fitting 12 ispreferably provided with a check valve (not shown) therein which permitsupward flow of well fluid into the interior of the pump receiver 20, butwhich prevents downward flow of fluid out of the pump receiver into thewell. The inlet fitting i2 is seated on an annular insert 13 which isdisposed in the major bore 44 in the lower fitting 45 and which isseated on a shoulder T4 therein.

The inlet fitting 12 also serves as a seat for the pump 2|, the latterbeing in its operating position when it is disposed in the pump receiver20 and seated on the pump seat provided by the inlet fitting; The pump2| is adapted to seat on the inlet fitting 12 automatically when it ismoved downwardly through the supply tubing i! into the pump receiver 20so that it automat- 8 ically assumes its operating position uponengaging the inlet fitting.

Except for certain modifications required to adapt it to the closedtubing system of the invention, the fluid-operated free pump 2| may beof conventional design and will not be described in detail. In general,the pump 2! includes a motor section and a pump section below the motorsection, the motor and pump sections respectively including coupledmotor and pump pistons (not shown). The motor section of the pump 2| isactuable by operating fluid under pressure delivered thereto by thesupply tubing 11, the operating fluid under pressure being adapted toenter the motor section of the pump through ports which serve as anintake 18 for the pump and which are in fluid communication with thesupply tubing when the pump is in its operating position. The ports ofthe intake 18 are formed in an intake fitting 79 which provides theaforementioned tapered head 35 and which is connected to the upper endof a tubular rod 80 extending upwardly from the motor section of thepump 2|, the rod being adapted to cohvey the operating fluid underpressure from the intake to the motor section of the pump.

After the operating fluid admitted to the motor section of the pump 2!through the intake 18 has performed its function, it is discharged fromthe motor section through ports forming an exhaust 8| for the pump. Whenthe pump 2| is in its operating position, the exhaust 8| communicateswith an annular space 82 between the pump and the liner 52 in the majorbore 41 in the upper fitting 42, the annular space 82 communicating withthe return tubing it through the port 5i in the liner, the lateralpassage 50 in the fitting 42 and the minor bore 49 in this fitting.Thus, the operating fluid under pressure in the supply tubing I'I flowsthrough the motor section of the pump 2| to actuate it and is dischargedinto the return tubing I8 as spent operating fluid.

In order to prevent direct flow of operating fluid between the supplyand return tubings l1 and I8 by way of the pump receiver 28, I providesealing means comprising an annular sealing element 86 which is carriedby the pump 2| intermediate the intake 78 and the exhaust 8| and whichis adapted to engage the liner 52 above the port 5| therein when thepump is in its operating position. The annular sealing element 86 ispreferably of the O-ring type and is formed of oil-resistant rubber, orother suitable material. The pump 2! carries another, similar annularsealing element 81 below the exhaust 8|, this sealing element beingadapted to engage the liner 52 between the port 5! therein and thegroove 82 of the passage means 56 when the pump is in its operatingposition. Thus, the annular sealing elements 86 and 81 isolate theintake 78 and'the exhaust 8! when the pump 2| is in its operatingposition so that the intake may communicate only with the supply tubingl1 and so that the exhaust may communicate only with the return tubing18.

As previously indicated, the pump section of the pump 2! is providedwith an inlet (not shown specifically) at its lower end. through whichwell fluid is adapted to enter the pump section by way of the inletfitting 72. The pump section of the pump is also provided with portsforming an outlet 88 for production fluid discharged'by the pumpsection, the outlet communicating with an annular space 89' between thepump and the sleeve 43 connecting the upper and lower fittings 42 and 45of the pump receiver 20. The annular space 89 extends downwardly-.production fluid discharged by the pump section of the pump 2| throughthe outlet 88 flows.

through the annular space 89 and the annular chamber 9| into the lateralpassage 55 in the lower fitting 45 and thence upwardly through theminorbore 54 in this fitting into the production tubing I9.

.- It will be noted that the annular sealing element 81 is disposedbetween the exhaust 8| and the outlet 88 so that it prevents flowbetween the return and production tubings l8 and' I9 when-the pump is inits operating position. Also,

since the pump 2| is seated onthe inlet fitting 12 when in its operatingposition, the pump seat provided by the inlet fitting serves to preventdirect flow between the well and the production tubing l9. Flow betweenthe return and produc-' tion tubings l8 and I9 by way of the passage.

means 58 is prevented by the spring-loaded valve 63 when the pump is inoperation, as hereinbefore indicated. 1

Considering the operation of the embodiment of the inventionhereinbefore described, it will be assumed that the pump 2| is inoperation to pump fluid from the well upwardly through the productiontubing l9 to the surface. Under such conditions, the pump 2| is in itsoperating position in the pump receiver 20 wherein it is: seated on theinlet fitting 12 and the aforemen-p tioned valve means in-the pumphea-d29 respectively connects the supply, return'and pro-' ductiontubings l7, l8 and 19 to the supply, re-

turn and production lines 3|, 32 and 33. Thus,

operating fluid under pressure is conveyeddownwardly to the pump 2 Ithrough the supply tubing I1 .and enters the motor section of the pumpthroughthe intake 18 to actuate the pump, spent operating fluid beingdischarged-into the return tubing I8 through the-exhaust-8l andbeing-conveyed upwardly in the well to the surface by'the return tubing.The well fluid entering the pump section of the pump 2| through itsinlet is dis-- chargedintotheproductiontubing l9 throughgm the outlet 88and is conveyed upwardly: in the welltothe-surface asproduction fluid.Itwill be. apparent that, with this construction, the

spent. operating fluid is returned to the surface separately from theproduction fluidso that it maybe .re-used to actuate the pump-2|, whichis ajprimary feature .of the invention.

In the event that removal of the pump 2 l'from thewell is necessary.in-order to service or repair the pump, or for any other reason, theoperator sets the handle 30 controlling the valve means,

in the pumphead 29 ina position such that the;

valve means connects the supply line 3| to the return tubing =-|8 .sothat operating fluid under;

pressure ,flows. downwardly into the'well through.- the-return-tubing.Preferably, the valve means also connects-the supply tubing H to thereturn line -32- under such conditions, and prevents .fluidcommunication between the productiontubing';

l9 andtheproduction line 33. -Alternatively,'.

fluid flow through-the production tubing |9-and--- the, production line-33 may be'prevented by,"

ee n 3* :Val 9, in? h -erq uetien; li e at:

tubing I! in a substantially fluid-tight though it will be understoodthat this function is-- preferably performed by the valve means in thepump head 29.

Under the conditions outlined in the preceding,

above the spring-loaded valve 63 is insuflicient to open the valve. Thepressure of the operat-,

ing fluid entering the annular chamber 9| in the foregoing manner isapplied to an annular area 95 atthe lower end of the pump 2| so as tounseat the pump from the inlet fitting I2 and is then applied totheentire area of the pump so as to moveit upwardly in the pump receiver20,upward fiowof the operating fluid applied to the lower end of the pumpin this manner past the pu p being prevented by the annular sealingelements iifi and 81 which engage the liner 52. Afterthe pump 2| hasmoved upwardly in the pump receiver 29 a distance such that the annularsealing elements 86 and 81 disengagethe liner 52, upward flow ofoperating fluid past the pumpis preventedby packing devices 96 and 91which are carried by the rod and which are adapted to engage the innerwall of the supply manner. the portions of thepump-2l which carry theannular sealing elements ;86 and 81 preferably being of smaller diameterthan the internal diameter of the supply tubing so as to prevent damageto these sealingfelements during movement of the pump through 1 thesupply tubing. After the pump has cleared-the port 5| in the liner 52,the downward flow of operating fluid through the return tubing I8 isapplied to the lower end of the pump to move it upwardly directlythrough the lateral passage 50 and the port 5|. Thus, the'operatingfluid under pressure flowsth'rough the passagemeans 58 to unseat thepump 2| and to move it upwardly in.

the, pump receiver 20 a sufficient distance to clear; the .port 5|.Thereafter, the downward flowof' operating fiuidunder pressure throughthe return tubing l8 enters the pump receiver 29 ing. the aforementionedvalve 94, or by means of" the valve means in the pump head 29. It

willmbe-noted that, since the standing valve 66 prevents downward flowof production fluid out of the production tubing l9 and into the pump Ireceiver, none of the production fluid can enter 'the pump receiverduring the pump-removal operation-which is an important feature since itprevents sand and other foreign matters which may Joe; in the productionfluid from entering t awin e v r- It will be noted that, under theconditions hereinbefore outlined, the operating fluid in the supplytubing I1 above the pump 2| is returned 7 to the reservoir through thereturn line 32 during placed in fluid communication with the supply line3I and the return tubing I8 is placed in communication with the returnline 32. Thus, the operating fluid under pressure entering the systemthrough the supply line 3| acts on the upper end of the pump 2I to moveit downwardly through the supply tubing I1 and into its operat ingposition in the'pump receiver wherein it is seated on the inlet fitting,I2, the operating fluid previously introduced below the pump during thepump-removal operation being displaced upwardly through the returntubing I8 and into the return line 32 leading to the reservoir on thesurface. During the operation of installing the pump, the valve 94, orthe valve means in the pump head 29, preferably prevents flow throughthe production tubing I9 and production line 33 so that all of the fluidemployed during the pump-removal operation is returned to the reservoirduring reinstallation of the pump. However, it will be understood thatif the operating fluid in the supply tubing has become contaminatedprior to reinstallation of the pump 2| for any reason, returning suchcontaminated-operating fluid to the reservoir may be avoided bypreventing fluid flow through the return tubing I8 and by permittingfluid flow through the production tubing I9.

As will be apparent, one advantage of the embodiment hereinbeforediscussed is that it is possible to remove and reinstall the pump 2|with substantially no loss of operating fluid from the system, theproduction tubing I9 being isolated from that portion of the systemreserved for the operating fluid during both the pump-removal operationand the pump-installation operation.

It will also be noted that since the production fluid comes in contactonly with the production tubing I9, because of the fact that the supplyand return tubings I 1 and I8 are located without the production tubing,paraffin control is'simplified and damage to the system by the action ofany corrosive substances which may be present in the production fluid isminimized, such corrosion damage being restricted to the productiontubing.

Another advantage is that the production fluid flowing through theannular chamber 9| during operation of the pump 2I continuously washesaway any sand deposits tending to form at the junction of the pump andthe inlet fitting I2 to prevent obstructing the pump seat provided bythis fitting.

nected to the casing head H6 is a closed tubing system of the inventionwhich comprises supply, return and production tubings set side-by-sideand respectively identified by the numerals H1, H8, and 9. As will bediscussed in more detail hereinafter, the tubings H7, H8 and II9 areinterconnected at their lower ends in fluid communication with eachother and with the well by a tubular pump receiver I20 which is aligned.

with and which, in effect, forms a downward extension of the productiontubing I9. The pump receiver I20 provides an operating position for afluid-operated, free pump I2I which is movable downwardly through theproduction tubing II9 into its operating position in the pump receiver,the internal diameter of the pump receiver being substantially equal tothat of the production tubing. As in the previously discussedembodiment, the supply tubing H1 is adapted to convey operating fluidunder pressure downwardly in the well to the pump I2I to actuate thepump, and the return tubing H8 is adapted to convey spent operatingfluid discharged by the pump upwardly in the well. The pump I 2| isadapted to receive well fluid from the well and to discharge it into theproduction tubing II9 as production fluid, the production Q tubing thenconveying the production fluid upwardly to the surface.

As in the previously described embodiment, the lower ends of the tubingsI I! to I I 9 and the pump receiver I20 may be enclosed by a gas anchorI22 having a perforated-barrel I23 which is closed at its upper andlower ends by heads I24 and I25,

dle I30 to direct flows of fluid through the tub ings in the propermanner. Supply, return and production lines I3I, I32 and I33 are alsoconnected to the pump head I29 and are adapted to be connected in fluidcommunication with the supply, return and production tubings H1, H8

and H9, respectively, by the valve means in the pump head duringoperation of the pump I2I.

As in the preceding embodiment, the supply line I3I leads to a suitablesource of operating fluid under pressure, the return line I32 leads to areservoir for the source and the production line I33 leads to a suitablepoint of disposal for the production fluid.

Referring now to Figs. 9 and 10 of the drawqings, the pump receiver I20is, as previously in- Turning now to the embodiment of the inven'dicated, aligned with and connected to the lower end of the productiontubing II9, the pump receiver having at its upper end a sleeve I40 whichis threaded onto the lower end of the production tubing. For a reasonwhich will be pointed out hereinafter, the internal diameter of thesleeve I49 is slightly greater than that of the produc tion tubing I I9.The lower end of the sleeve I40 is threaded into the upperend of a majorbore MI in an upper fitting I42 which forms part of the pump receiverI20, a sleeve I43 being threaded into the lower end of this major bore.The lower end of the sleeve I43 is threaded into the upper end of amajor bore I44 in a lower fitting I45 of the'pump receiver 'I20,an inletsleeve.

I46 being threaded into the lower end of the spaced laterally from themajor bore I4I therein, the lower ends of the supply and return tubingsH1 and H8 being threaded into the upper ends of the minor bores I41 andI48, respectively. The minor bore I41 communicates with the interior ofthe tubular pump receiver. I29 through a lateral passage I49 in theupperfitting I42 and through a port I50 in a liner II which is pressedinto the major bore MI in the upper fitting. The minor bore I48communicates with the interior of the pump receiver I through a lateralpassage I52 in the upper fitting I42 and through a port I53 in the linerI 5I. As best shown in Fig. 11 of the drawings, the upper fitting I 42is also provided with a passage I54 therethrough which communicates withthe interior of the pump receiver above the lateral passage I49 and theport I50 and which communicates with the interior of the pump receiverbelow the lateral passage I52 and the 'port I53. As will be discussed inmore detail hereinafter, the passage I54 is adapted to convey productionfluid discharged by the pump I2I upwardly through the upper fitting I42and into the production tubing II 9 above the body of the pump I2I. Itwill be apparent that, with this construction, the pump receiver I20interconnects the lower ends of the supply, return and productiontubings H1, H8 and H9 in fluid communication with each other and withthe well.

"The embodiment presently under consideration is provided with a passagemeans I58 for applying a downward flow of fluid through the returntubing II8 to the lower end of the pump I2I to unseat the pump and moveit upwardly out of the pump receiver I20 when removal of the pump isdesired for any reason, this passage means including a tube I59 which isthreaded at its u per end into the lower end of a bore I60 communicatingwith the minor bore I48 in the upper fitting I42. The lower end of thetube I59 is threaded into the upper endof a bore IBI ad acent the majorbore I44 in the lower fitting I45. the bore IBI communicating with anannular chamber I62 within the pump receiver I 20 at the lower end ofthe pump I2I through lateral passages I53 and an annular groove. I64. Inactual practice, instead of forming the bore I 6| directly in the lowerfitting I45, I' prefer to form this bore and the lateral passages I63and the groove I 64 in an insert I65 which is disposed in a bore I66formed in the lower fitting proper, the tube I59 being threadedlyconnected to this insert and the insert carrying sealing rings I61 aboveandbelow-the annular groove I64. 4 This construction facilitatesassembling thenpper. and lower fittings I42 and I54, the intermediatesleeve I 43 and the tube I59 since the insert I65 may slide in the boreI66 while the intermediate sleeve I43 is being threaded intov theupperand lower fittings.

Disposed in 'the lower end of the major bore I44 in the lower fittingI45 of the pump receiver I20f'an'd extending downwardly into the inletsleeve I 46', is an inlet fitting I12 for the pump I2I, thelatter havingan inlet which is adapted to'receive well .fluid. from the well.vthrough the inletfittingwhen the pump is in its operatingpositipiiaswill be discussed in more detail here- White-514 isr k wn. ii e, the inlet fitting I12 is preferably provided with a checkvalve (notshown) therein which permits upward flow of well fluid into' theinterior of the pump receiver I20, but which prevents downward flow offluid out of the pump receiver'into the well..,'

The inlet fitting I12 is seated on an annular insert I13 which isdisposed in the major bore I44 in the lower fitting I45 and whichis-seated on a shoulder I14 therein. i

As in the previously discussed embodiment,

the inlet fitting I12 also serves as a seat for thef pump I2I, thelatter being in its operating position when it is disposed in the pumpreceiver I20 and seated on the pump seat provided by the inlet fitting.The pump I2I is also adapted to seat on the inlet fitting I12automatically when it is moved downwardly through the production tubingII9 into the pump receiver I20 so that it automatically assumes itsoperating position.

The pump I2I is substantially identical to the pump 2I and includes amotor section which is actuable by operating fluid under pressure.delivered thereto through the supply tubing II1, the operating fluidunder pressure being adapted to enter the motor section of the pumpthrough an intake I18 which comprises an annular groove I19 andregistering ports I80, the groove I19 registering with the port I50 inthe liner I5I when the pump is in its operating position. After theoperating fluid admitted to the motor sec-- tion of the pump I2I throughthe intake. I58

has actuated the pump, it is discharged from the motor section throughports forming an exhaust IBI for, the pump. When the pump ,I2I is in itsoperating position, the exhaust I8I communicates with an annular spaceI82 between the pump and the linear I5I in the major bore MI I48 in thisfitting. Thus, the operating fluid under pressure in the supply tubing,II1 flows through the motor section of the pump I M to actuate it andis discharged into the return tubing I I8 as spent operating fluid.

The embodiment under consideration includes sealing means for preventingdirect flow between the supply, return and production tubings I I1,-.

H8 and H9 when the pump I2I is in its operating position, such sealingmeans comprising, annular sealing elements I85, I86 and I81 carried bythe pump. The. annular sealing element I85. is located abovethe intakeI18 and serves to separate the supply tubing I H from the produc-.-

tion tubing II9 when the pump is in its operating position. The sealingelement I86 isdisposed between the intake I18 and the exhaust IBI andprevents direct flow between the supply tubing H1 and the return tubingII8 when the pump is in its operating position, the sealing element I81being disposed below the exhaust I8I and, as will be discussedhereinafter, being adapted to prevent mixing of the production fluid andthe spent operating fluid. Thus, the annular sealing elements I to I81isolate the intake I18 and the exhaust I8I when the pump I2I is in itsoperating position so that the in-" take may communicate only with thesupply tubing .I I1. and so thatthe exhaust may communi cate onlywiththe return tubing I I8. x

As previously suggested, the pump section of the pump I2I is providedwith an inlet (not speciflcally shown) at its lower end through whichwell fluid is adapted to enter the pump section by way of the inletfitting I72. The pump section is also provided with ports forming anoutlet I88 for production fluid discharged by the pump section, theoutlet communicatin with an annular space I89 between the pump and thewall of the tubular pump receiver 128. The previously mentioned passageI54 through the upper i'itting I42 communicates with the annular spaceI89 and communicates with the interior of the pump receiver above thebody of the pump so that production fluid discharged into the'annularspace I89 through the outlet IE3 is conveyed upwardly into the upper endof the pump receiver by the passage I54 and then flows upwardly into theproduction tubing H9. t will be noted that the pump I2I includes a rodI9I which extends upwardly from the motor section of the pump and whichcarries packing devices I92 and I93, such packing devices being disposedin the enlarged upper sleeve I46 of the pump receiver l2!) when the i inits operating position'so' that the production fluid may flow upwardlypast the packing devices into the production tubing I I9,

In order to prevent the production fluid di.,-

charged through the outlet I38 from flowing downwardly into the annularchamber I32 and thence upwardly through the passage means 554! into thereturn tubing H3 when the pump is in operation, the pump carries anannular sealing element I96 which i disposed below the outlet and whichengages a liner I55 in the major bore H4 in the lower fitting I45 whenthe pump is in its operating position. Thus, th annular sealin elementltd serves to isolate the outlet I88 from the return tubing so that itcommunicates only with the production tubing when the pump is in itoperating position. Also, since the pump is seated on the inlet fittingI32 when in its operating position, the pump seat provided by the inletfitting serves to prevent direct flow between the and the return tubingIIB.

Considering the operation of the embodiment of the invention disclosedin Figs. 6 to 11 of the drawings, it will be assumed that the pump .I2Iis in operation to pump fluid from the well upwardly through theproduction tubing H9 to the surface. Under such conditions, the pump isin its operating position in the pump receiver I 26 wherein it is seatedon the inlet fitting I72, and

the aforementioned valve means in the pump head I29 respectivelyconnects the supply, return and production tubings III, I I8 and IE9 tothe supply, return and production lines I3I, I32 and I33. Thus,operating fluid under pressure is carried downwardly to the pump iZIthrough the supply tubing It! and enters the motor section of the pumpthrough the intake I78 to actuate the pump, spent operating fluid beingdischarged into the return tubing H8 through the exhaust I3! and beingconveyed upwardly in the well to the surface by the return tubing. Thewell fluid entering the pump section of the pump it: through its ins-tis discharged into the production tubing H9 through the outlet I88 andis conveyed upwardly in the well separately from the spent operatingfluid.

In the event that removal of the pump I2I is necessary, the operatorsets the handle I39 controlling the valve means in the pump head I29 ina position such that the valve means connects the supply line iii to thereturn tubing H8 so the. operating fluid under pressure fiOWs downwardlyinto the well through the return tubing.

Preferably, the valve mean also connects the seated on the inlet fittingI12.

production tubing H9 to the production line I33 under such conditions sothat the production fluid above the pump' i2| may enter the productionline. The supply tubing I Il may remain connected to the supply line I3Iunder these conditions. Alternatively, fluid flow through the supplytubing Ii! may be prevented by closing a valve I98 therein, althoughthis function'may be performed by the valve means in the pump head I29.

Under the conditions outlined in the preceding paragraph, operatin fluidunder pressure flows downwardly through the return tubing H8 and intothe annular chamber I62 at the lower end of the pump I2I by way of thepassage means I58 and acts on an annular area I97 at the lower end ofthe pump so as to unseat the pump from the inlet fitting H2 and thenacts on the entire area of the pump so as to move it upwardly in thepump receiver I29, upward flow or the op erating fluid applied to thelower end of the pump in this manner past the pump being prevented bythe annular sealing elements I85 to E8? and IE5. After the pump I2I hasmoved upwardly in the pump receiver I20 a distance such that the annularsealing elements I85 to I8! and I95, disengage the liners I5I and H35.upward flow of operating fluid past the pump is prevented by the packingdevices I92 ,andsI93 which, by this time, have moved upwardly out of theenlarged upper sleeve I49 and into the production tubing proper. Thepacking devices I92 and I93 are adapted to engage the inner wall of theproduction tubing I I9 in a substantially fluid-tight manner, theportions of the pump which carry the annular sealing elements I85 to I87and I96 preferably being of smaller diameter than the internal diameterof the production tubing so as to prevent damage to these sealingelements during movement of the pump through the production tubing.Continued downward flow of operating fluid under pressure through thereturn tubing IIB ultimately results in upward movement of the pump E2Ithrough the production tubing IE9 to the surface so that it may beremoved from the production tubing through the pump head I29, theproduction fluid in the tubing I I9 above the pump being displaced intothe production line I33.

in the event that the supply tubing I I1 is connected in fluidcommunication with the supply line I3I during the pump-removaloperation, a downward flow of fluid through the supply tubing occurs toassist in removing the pump once the pump has cleared the port I58 inthe liner I5I.

During the foregoing pump-removal operation, flow of the operating fluidemployed to remove the pump out of the pump receiver I20 into the wellis prevented by the check valve in the inlet fitting I12. a

When reinstallation of the pump I2I, or installation of a replacementpump I2I, is desired, the pump to be installed is inserted into theupper end of the production tubing [I9 through-the pump head I29. Theoperator then sets the handle I39 controlling the valve means in thepump head in a, position such that the production tubing I I9 is placedin fluid communication with the Supply line I3I. Thus, the operatingfluid under pressure entering the system through the supply line 52%|acts on the upper end of the pump to move it downwardly through theproduction tubing H9 and into its operating position in the pumpreceiver I29 wherein itis The operating 17 fluid previously introducedbelow the pump during the pump-removal operation may be displacedupwardly through the return tubing H8, or through both the returntubings H8 and the supply tubing I H. The operating fluid displacedupwardly in this manner may be returned to the reservoir for reuse ifthe wallsof the production tubing H9 are relatively free from sand orother abrasive material, although it may be desirable to dispose of suchdisplaced operating fluid if abrasive matter is present. In the lattercircumstance, it would be necessary to replenish the operating fluidlost from the system with fresh operating fluid.

As in the case of the previously described embodiment, since theproduction fluid comes in contact only with the production tubing I [9,because of the fact that the supply and return tubings H1 and H8 arelocated without the production tubing, paraffin control is simplifiedand damage to the system by the action ofany corrosive substances whichmay be present in the production fluid is minimized, such corrosiondamage being restricted to the production tubing.

It will be noted that in either of the embodiments hereinbeforedescribed, the tubing forthe pump may be of relatively large internaldiameter so that a pump of relatively large external diameter may beemployed to provide maximum capacity for the motor and/or pump sectionsof the pump.

An important advantage of the embodiment illustrated in Figs. 6 to 11 ofthe drawings is that it permits employing a production tubing H9 ofrelatively large internal diameter so as to minimize frictional lossesbetween the production fluid stream and the production tubing, which isimportant in wells permitting the use of a pump having a pump section oflarge-capacity and a motor section of small capacity.

Although I have disclosed exemplary embodiments of the invention forpurposes of illustration, it will be understood that various changes,modifications and substitutions may be incorporated in such embodimentswithout departing from the spirit of the invention.

I claim as my invention:

1. In a closed, fluid-operated, free-pump system for a well, thecombination of: a supply tubing set in the well and adapted to conveyoperating fluid downwardly into the well from the surface; a returntubing set in the well and adapted to convey spent operating fluidupwardlyin' the well to the surface; a production tubing set in the welland adapted to convey fluid produced by the well upwardly therein to thesurface; means for interconnecting the lower ends of said tubings influid communication with each other and with the well; and afluid-operated; free pump movable in one of said tubings into anoperating position at the lower endthereof; said pump having an intake,an exhaust, an in-i let andan outlet which communicate withsaid supplytubing, said return tubing, the well and said production tubing,respectively, when said pump is in said operating position.

2. In aclosed, fluid-operated, free-pump systtem for a well, thecombination of: three tubings set in the well and respectively adaptedto convey operating fluid downwardly into the well from the surface,spent operating fluid upwardly; in the well to the surface and fluidproduced by theiwell upwardly therein to the surface; meansforinterconnecting the lower ends of said tubings in fluid communicationwith each other and with the 18 well; a pump seat at the lower end ofand aligned with one of said tubings; and a fluid-operated, free pumpmovable in said one tubing into an operating position at the lower endthereof wherein it is seated on said pump seat, said pump having anintake, an exhaust and an outlet which communicate with said tubings,respectively, when said pump is in said operating position, and havingan inlet which communicates with the well when said pump is in saidoperating position.

3. In a closed, fluid-operated, free pump system for a well, thecombination of a supply tubing set in the well and adapted to conveyoperating fluid downwardly into the well from the surface; a returntubing set in the well and adapted to convey spent operating fluidupwardly in the well to the surface; a production tubing set in the welland adapted to convey fluid produced by the well upwardly therein to thesurface; a tubular pump receiver at the lower end of and aligned withone of said tubings, said pump re-.' ceiver being connected to the lowerendsof said tubings in fluid communication therewith and being in fluidcommunication with the well; and a fluid-operated, free pump movable insaid one tubing and movable into an operating position in said pumpreceiver, said pump having an intake, an exhaust, an inlet and an outletwhich communicate with said supply tubing, said return tubing, the welland said production tubing, respectively, when said pump is in saidoperating position in said receiver.

4. A closed system as set forth in claim 3 including sealing devices fornormally preventing direct flow of fluid between said tubings and thewell when said pump is in said operating position. 5. In a closed,fluid-operated, free-pump system for a well, the combinationof: a supplytubing set in the well and adapted to convey operating fluid downwardlyinto the well from the surface; a return tubing set in the well andadapted to convey spent o'perating fluid upwardly in the well to thesurface; a production tubing set in the well and adapted to convey fluidproduced by the Well upwardly therein to the surface; a tubular pumpreceiver connected to the lower ends of said tubings in alignment withone of said tubings, said pump receiver communicating at its upper endwith said one tubing and having substantially the same internal diameteras said one tubing, and said pump receiver having passages which providefluid communication between the others of said tubings andsaid pumpreceiver and between the well and said pump receiver; a'pump seatcarried by said pumppre-i ceiver at the lower end thereof and inalignment therewith; a fluid-operated, free pump movable in said onetubing and movable into an operating position in said pump receiverwherein it is seated on said pump seat, said pump having an intake, anexhaust, an inlet and an outlet which communicate with said supply,tubing,j ,said return'tubing, the well and said production tubing,respectively, when said pump is in said operating position; and sealingdevices for normally preventing direct flow of fluid between saidtubings and the well by way of said pump receiver when said pump is insaid operating position.

6. In a closed, fluid-operated, free-pump system for a well,the'combination of: a supply tubing set in the well and adapted toconvey operating fluid downwardly into the well from the surfaces; areturn tubing set in the well and adapted to convey spent operatingfluid upwardly in the well to the surface; a production tubing set inthewell and adapted .to convey. fluid produced by. the

well upwardly therein to the surface; a tubular pump receiver connectedto the lower ends of said tubings in alignment with one of said tubings,said pump receiver communicating at its upper end with said one tubingand having substantially the same internal diameter as said one tubing,and said pump receiver having passages which provide fluid communicationbetween the others of said tubings and said pump receiver and betweenthe well and said pump receiver; a pump seat carried by said pumpreceiver at the lower end thereof and in alignment therewith; afluid-operated, free pump movable in said one tubing and movable into anoperating position in said pump receiver wherein it is seated on saidpump seat, said pump having an intake, an exhaust, an inlet and anoutlet which communicate with said supply tubing, said return tubing,the well and said production tubing, respectively, when said, pump is insaid operating position; sealing devices for normally preventing directflow of fluid between said tubings and the well by way of said pumpreceiver when said pump is in said operating position; a chamber in saidpump receiver between said pump seat and said pump; and passage meansproviding fluid communication between said chamber and one of said othertubings so as to deliver fluid flowing downwardly through said one othertubing to said chamber to move said pump upwardly out of said pumpreceiver and through said one tubing to the surface.

'7.'In a closed, fluid-operated, free-pump system for a well, thecombination of a supply tubing set in the well and adapted to conveyoperating fluid downwardly into the well from the surface; a returntubing set in the well and adapted to convey'spent operating fluidupwardly in the well to the surface; a production tubing set in the welland adapted to convey fluid produced by the well upwardly therein to thesurface; .a tubular pump receiver connected to the lower ends of saidtubings in alignment with one of said tubings, said pump receivercommunicating at its upper end with said one tubing and havingsubstantially the same internal diameter as said one tubing, and saidpump receiver having passages which provide fluid communication betweenthe others of said tubings and said pumpreceiver and between the welland said pumpreceiver; 'a pump seat carried by said pump receiver at thelower end thereof and in alignment therewith; a fluid-operated, freepump movable in said one tubing and movable into an operating 'positionin said pump receiver wherein it is seated on said pump seat, said pumphaving an intake, an exhaust, an inlet and an outlet which communicatewith said supply tubing, the welland 'said production tubing,respectively; when said pump is in said operating position; sealingdevices for normally preventing direct flow of fluidbetwe'en saidtubings and the well by way 'of'said pump receiver when said pump is insaid operating position; a chamber in said pump receiver'between saidpump seat and said pump; passage means providing fluid communication"between said chamber and one of said other tubings so as to deliverfluid flowing downwardly through said one other tubing to said chamberto move said pump upwardly out of said pump receiver and through saidone tubing to the surface; and another sealing device for normallypreventing flow of fluid between said passage means and said productiontubing.

8. A closed system as set forth in claim 7' wherein said other sealingdevice comprises a spring-loaded valve in said passage means.

9. A'closed system as set forth in claim '7 wherein said other sealingdevice comprises an annular sealing element adapted to be disposedbetween said pump and said pump receiver.

10. In 'a closed, fluid-operated, freepump system :for'a well, thecombination of: supply, return and production tubings set in the welland respectively adapted to convey operating fluid downwardly into thewell from the surface, spent operating fluid upwardly in the well to thesurface and fluid produced by the well upwardly therein to the surface;means for interconnecting the lower ends of said tubings in fluidcommunication with each other and with the well; a fluid-operated, freepump movable in one of said tubings into an operating position at thelower end thereof, said pump having an intake, an exhaust, an inlet andan outlet which communicate with said supplytubing, said return tubing,the well and said production tubing, respectively, when said pump is insaid operating position; means for normally preventing direct flow offluid between said tubings and the well by way of said interconnectingmeans when said pump is in said operating position; and passage meanscommunicating with one of the others ofsaid tubings and with said onetubing for applying a downward flow of fluid through said one othertubing to the lower end of said pump to move said pump upwardly from itsoperating position through said one tubing to the surface. 7

11. A closed system as set forth in claim 10 wherein said supply tubingis said one tubing.

12. A closed system as set forth in claim 10 wherein said productiontubing is said one tubing.

13. A closed system as set forth in claim 10 wherein said one othertubing with which said passage means communicates is said return tubi14. A closed system as set forth in claim 10 wherein said supply andreturn tubings are without said production tubing 15. A closed system asset forth in claim 10 wherein said one tubing is of larger diameter thanat least one of the others of said tubings.

-.16. A closed system as set forth in claim 10 wherein said one tubingis of larger diameter than either of the others of said tubings.

17. A closed system according to claim 1*0 wherein said productiontubing is of larger diameter than at least one of the other two tubings;

18. A closed system as defined in claim 10 wherein said productiontubing is of larger diameter than either of the other two tubings.

19. A closed system according to claim 10 wherein said tubings aredisposed side-by-side.

20. In a closed, fluid-operated, free-pump system for a well, thecombination of: supply, return and production tubings set side-by-sidein the well and respectively adapted to convey operating fluiddownwardly into the well from the surface; spent operating fluidupwardly in the well to the surface and fluid produced by the wellupwardly therein to the surface; a tubular pump receiver at the lowerend of and aligned with one of said tubings, said pump receiver beingconnected to the lower ends of said tubings and being in fluidcommunication with said tubings and withlthe well; a pump seat carriedby said pump receiver and disposed at the lower end thereof in alignmenttherewith; a fluid-operated, free pump movable in said one tubing andmovable into an operating position in said pumpre'ceiver wherein it isseated on said pump seat, said pump having an intake, an exhaust, aninlet and an outlet which communicate with said supply tubing, saidreturn tubing, the well and said production tubing, respectively, whensaid pump is in said operating position; means for normally preventingdirect flow of fluid between said tubings and the well through said pumpreceiver when said pump is in said operating position; and passage meanscommunicating with one of the others of said tubings and with said pumpreceiver above said pump seat for applying a downward flow of fluid insaid one other tubing to the lower end of said .pump to move it upwardlyout of said pump receiver and through said one tubing to the surface.

21. A closed system as set forth in claim 20 wherein said passage meanscommunicates with said return tubing and wherein said means forpreventing direct flow comprises a sealing device for preventing fluidcommunication between said return tubing and said production tubing whensaid pump is in said operating position, said sealing device comprisingan annular sealing element between said pump and said pump receiver.

22. A closed system as set forth in claim 20 wherein said passage meanscommunicates with said return tubing and wherein said means forpreventing direct flow comprises a sealing device for preventing fluidcommunication between said return tubing and said production tubing whensaid pump is in said operating position, said sealing device comprisinga spring-loaded valve in said passage means.

23. A closed system as set forth in claim 20 wherein said one tubing issaid production tubing.

24. A closed system as set forth in claim 20 wherein one tubing is saidsupply tubing.

25. A closed system as set forth in claim 20 wherein said one tubing isof larger diameter than either of the others of said tubings.

26. A closed system as set forth in claim 20 wherein said productiontubing is of larger diameter than either of the others of said tubings.

27. In a closed, fluid-operated, free-pump system for a well, thecombination of a supply tubing set in the well and adapted to conveyoperating fluid downwardly into the well from the surface; a returntubing set in the well and adapted to convey spent operating fluidupwardly in the well to the surface; a production tubing set in the welland adapted to convey fluid produced by the well upwardly therein to thesurface; a tubular pump receiver at the lower end of and aligned withsaid production tubing and connected to the lower ends of said tubings,said pump receiver communicating at its upper end with said productiontubing, communicating at its lower end with the well and communicatingintermediate its ends with said supply and return tubings; afluid-operated, free pump movable in said production tubing and movableinto an operating position in said pump receiver, said pump havingadjacent its upper end an intake and an exhaust respectivelycommunicating with said supply and return tubings when said pump is insaid operating position, and having adjacent its lower end an outlet,said inlet communicating with the well when said pump is in saidoperating position; a passage communicating with said pump receiver at apair of vertically spaced points, said outlet of said pump communicatingwith the lower end of said passage when said pump is in said operatingposition, and the upper end of said passage communicating with said'pumpreceiver above said intake and said exhaust when said pump is in saidoperating position to convey fluid from said outlet into saidproductiontubing; and sealing devices for preventing direct flow between saidtubings and the well when said pump i in said operatingposition.

' 28. In a closed, fluid-operated, free-pump system for a well, thecombination of supply, return and production tubings set' in the welland respectively adapted to convey operating fluid downwardly into thewell from the surface, spent operating fluid upwardly in the well to thesurface and fluid produced by the well upwardly therein to the surface;a tubular pump receiver at the lower end of and aligned with said supplytubing, said pump receiver being connected to'the lower ends of saidtubings in fluid communication therewith and being in fluidcommunication with the well; a fluid-operated, free pump movable in saidsupply tubing into an operating position in said pump receiver, saidpump having an intake, an exhaust below said intake, an outlet belowsaid exhaust and an inlet below said outlet, said intake, said exhaust,said inlet and said outlet respectively communicating with said supplytubing, said return tubing, the well and said production tubing whensaid pump is in said operating posiiton; an annular sealing elementcarried by said pump intermediate said intake and said exhaust andengageable with said pump receiver when said pump is in said operatingposition; another annular sealing element carried by said pumpintermediate said exhaust and said outlet and engageable with said pumpreeciver when said pump is in said operating position; and sealing meansproviding a fluid-tight seal between said inlet and said outlet whensaid pump is in said operating position.

29. A closed system according to claim 28 in- I cluding a passagecommunicating at one end with said return tubing and at its other endwith said pump receiver at a point which is intermediate said otherannular sealing element and said sealing means when said pump is in itsoperating position, said system, including a sealing device for normallypreventing flow from said return tubing through said passage to saidproduction tubing when said pump is in said operating position.

30. A system as set forth in claim 29 wherein said sealing devicecomprises a spring-loaded valve in said passage.

31. In a closed, fluid-operated, free-pump system, the combination of aprimary tubing and a pair of secondary tubings set in the well, saidprimary tubing being of a size to receive a fluidoperated, free pump andproviding for movement of the pump between an operating position at thelower end of said primary tubing and the surface; means interconnectingthe lower ends of said tubings, said interconnecting means havingpassage means providing fluid communication between one of saidsecondary tubings and said primary tubing and having passage meansproviding fluid communication between the other of said secondarytubings and said primary tubing; and inlet means connected to saidprimary tubing and having a passage providing fluid communicationbetween the well and said primary tubing, said inlet means having meansfor preventing flow of fluid from said primary tubing into the wellthrough said passage.

32. In a closed, fluid-operated, free-pump system, the combination of: aprimary tubing and a pair of secondary tubings set side-by-side in 23the well, said primary tubing being of a size to receive afluid-operated, free pump and providing for movement of the pump betweenan operating position at the lower end of said primary tubing and thesurface; means interconnectin the lower ends of said tubings, saidinterconnecting means having passage means providing fiuid communicationbetween one of said secondary tubings and said primary tubing and havingpassage means providing fluid communication between the other of saidsecondary tubings and said primary tubing; and inlet means connected tosaid primary tubing and having a passage providing fluid communicationbetween the well and said primary tubing, said inlet means having meansfor preventing flow of fluid from said primary tubing into the wellthrough said passage.

CLARENCE J. COBE-R-LY.

241 REFERENCES CITED The following references are of record in the dieof this patent:

UNITED STATES PATENTS Number Name Date 971,612 Holliday Oct. 4, 19101,630,902 Parrish May 31, 1927 10 1,765,921 Joy June 24, 1930 2,051,243Bowling Aug. 18, 1936 1 2,162,748 Richards 'et a1 June 20, 19392,230,787 Swain Feb. 4, 1941 2,230,830 Coberly Feb. 4, 1941 15 2,277,181Zuck Mar. 24, 1942 2,327,503 Coberly Aug. 24, 1943 2,338,903 CoberlyJan, 11, 1944

